Influence of Slope Height and Slope Ratio on Reliability of Channel Slopes

Abstract

【Background】 Slope height and slope ratio are the most important design parameters affecting slope stability. This paper investigates their combined impact on reliability of channel slopes in attempt to help optimize design and remediation of such slopes. 【Method】 The spatial variation of soil cohesion was calculated using the Karhunen-Loève (K-L) expansion method. With spatial variation of soil cohesion considered, the safety factor was calculated using the simplified Bishop method. The failing probability of the slope was calculated by the Monte Carlo simulation, from which we analyzed the influence of slope height and ratio on slope reliability. 【Result】 The reliability index gradually decreased with the increase in slope ratio. Regard less of spatial variability of the soil strength parameters, the reliability index gradually decreased with the increase in slope height. When the coefficient of variation of the cohesion was large and the coefficient of variation of the internal friction angle was small, the reliability index increased with the increase in slope height. Considering spatial variability of soil mechanical parameters, the reliability index increased with the increase in slope height, except when the variability of the cohesion was small and the variability of the internal friction angle was large. 【Conclusion】 In comparison to reducing slope height in exchange for slope stability, reducing the slope ratio was more effective in improving slope reliability and minimizing engineering risks.

Keywords

• channel slope
• reliability analysis
• slope height
• slope ratio
• limit equilibrium